1. Field of Invention
The present invention relates to an insulating support base for a cylindrical electric hot water tank.
2. Description of Prior Art
Hot water tanks are constructed with dome shaped bottom walls to withstand the load pressure within the tanks. These hot water tanks contain one, two or three electrodes which are spaced apart along the length of the tank. The bottom electrode is usually positioned about six inches above this dome shaped bottom wall and warms the water in that area to about 130.degree. F. However, the water at the bottom of the tank about the dome shaped bottom wall can fluctuate usually between 90.degree.-100.degree. F. as the water rises to the top of the tank. At these lower temperatures in the bottom of the tank, it has been found that bacteria growth can take place, and in fact the growth of bacteria legionella, and which is harmful to humans, has been attributed to this heat problem in the bottom of the tanks.
In order to resolve the above problem it is known in the prior art to provide an additional heating element on the dome shaped bottom wall to raise the temperature of the water within the tank at the bottom region thereof. However, because the bottom wall is exposed to air in the cavity adjacent its outer surface, the provision of that heating element has not been found efficient, as it also heats air and the metal of the tank as well as the water. The result is that the tank consumes much more electricity and the solution is costly.
Another cause of large temperature differentials within hot water heating tanks is the efficiency of the insulation between the inner and outer casings of the tank. Inproper insulation has results in excessive heat loss in certain regions of the tank. Proper insulation is particularly important in the lower regions of the tank to maintain the water temperature as high as possible to prevent bacterial growth.